Process for the electrochemical treatment of a construction comprising a porous medium, a corrodible substance disposed in the porous medium, the construction having electrically conductive properties, comprising the application of an external electrode (3) to a surface (2) of the construction, the external electrode (3) being connected to a terminal of a generator (6), the porous medium being connected to another terminal of the generator (6), and the application of the following four phases at least once: during a first phase lasting between 12 and 360 hours, passing a negative electric current which causes anions to migrate from the porous medium to the external electrode (3) and cations to migrate from the external electrode (3) towards the porous medium, then during a second phase lasting between 2 minutes and 100 hours, interrupting the circulation of the electric current, then during a third phase lasting between 2 minutes and 24 hours, passing a positive electric current, then during a fourth phase lasting between 1 and 120 minutes, interrupting the circulation of the electric current.